MySQL dump file and commented out lines

I have these lines at the top of a MySQL .sql file (dumped with phpMyAdmin):

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

But they all seem to be commented out. So will MySQL ignore them when the file is loaded back into a database? If so, why generate these lines at all?

 Answers

These are conditional comments aimed at certain versions of mySQL.

From here:

• MySQL version specific comments start with /*!
• And end with */
• Version numbers are always 5 digits
• Version numbers are in the format major release number, minor release number, revision number with the major being 1 digit and the minor and revision being 2 digits left-padded with 0’s
• Version specific comments will target any version equal to or higher than the version number listed